Tenants in seven Christchurch City Council housing units have to be found new homes after significant structural damage was found in the properties.
The damage was discovered in the HP Smith Courts Complex in Richmond on Friday and the person living in the most badly affected unit was moved out immediately. Others will be moved out over the next week.
The council said all tenants would be offered other places to live and help in moving.
One of the tenants, 89-year-old Bernie, said he accepted the need to move though he wasn't happy to go. "I've made good friends here, we're a little family," he said. "We get on well and it's going to be a bit of a shock to the system for some because some are a lot older than me."
The council said the units were evaluated for earthquake damage last year and found to be at an acceptable standard, but required further investigations for insurance purposes. Those further tests found structural damage.
Another block at the complex is considered to have only minimal damage, but more tests will be carried out.